


The Invitation

by buriednurbckyrd



Series: Dominant!Reader [5]
Category: Marvel Cinematic Universe, The Avengers (Marvel Movies)
Genre: Dom/sub, Dominant!Reader, Established Relationship, F/M, Multi, Reader Insert, Threesome - F/M/M, porn in part 2, proposed threesome
Language: English
Status: Completed
Published: 2018-01-25
Updated: 2018-02-20
Packaged: 2019-03-09 04:42:32
Rating: Explicit
Warnings: Creator Chose Not To Use Archive Warnings
Chapters: 2
Words: 4,648
Publisher: archiveofourown.org
Story URL: https://archiveofourown.org/works/13473927
Author URL: https://archiveofourown.org/users/buriednurbckyrd/pseuds/buriednurbckyrd
Summary: Bucky notices Steve behaving a little strange, and it seems to revolve around his girlfriend, Y/N.  What's going on?





	1. Chapter 1

**Author's Note:**

> Finally writing part five of my ongoing Dominant!Reader series! This will be split into two chapters, and it's also my first foray into Steve x Reader x Bucky. Enjoy!

The first time Bucky notices something odd is when Steve shows up at the gym wearing a hoodie instead of his usual tee shirt. He's wrapping his human hand to start beating on the punching bag when Steve starts running on the treadmill.

“What's with the sweater today? You're gonna overheat or somethin'.” The tips of Steve's ears turn pink.

“Uh, I forgot to do laundry. No big deal.” He doesn't meet his friend's eyes. 

“I could just lend you a shirt.” Bucky offers, and reaches for his bag. 

“That's okay!” Steve jumps off the machine. “I think I'll just skip today. Catch up on that laundry and um, other things. See ya later!” Bucky just sits confused as Steve actually sprints out of the gym. 

…

The second time is when he comes across Steve and Y/N, his girlfriend of several months talking in low voices. He can't really hear what they're saying and at first everything looks perfectly normal. He even considers crashing their conversation to tease them. But then he realizes Y/N has her delicate fingers wrapped around his best friend's throat with an intense look in her eyes. Before he can say or do anything, Clint and Natasha waltz in, arguing loudly. When Bucky looks back at the couple they're separated and wearing bright smiles. 

Bucky thinks he must have been seeing things and says nothing.

…

The third time Bucky is positive something fishy is going on, and he's determined to get to the bottom of it. Everyone is relaxing and celebrating a successful mission. But instead of playing pool with Sam or dancing with Y/N, Steve is nursing a beer and fidgeting in his seat. When he sees his best friend cast a nervous glance at his girlfriend for about the tenth time of the night, Bucky has had enough and sits down beside him.

“Is she hurting you?” He asks quietly, without preamble. Steve looks shocked and chokes on his beer.

“W-what?” He stutters.

“A few weeks ago you come to the gym wearing long sleeves to work out, something you never do,” Bucky says. “You spook when I offer to lend you a shirt, like you have something to hide. Then the other day I swear I see the two of you talking in the kitchen with _her hand around your throat._ ” Steve turns pink and looks around as if to check that no one else is listening.

“Look, it's nothing like that.” He whispers.

“What is it then? Because unless you tell me, I'm hauling her butt to Fury and filing an official complaint against her.”

“No!” Steve shouts, and everyone stops talking and looks over at them. Y/N looks concerned and takes a step forward. Bucky watches Steve make eye contact with her and give a sharp shake of his head. “Uh, sorry, just almost dropped my phone.” He says to the room and turns back to Bucky, with a serious expression. “Look. I swear to you there's nothing like that going on.”

“Just tell me the truth!” 

“You wouldn't believe me if I did!”

“Try. Me.” Bucky hisses. Steve's face burns bright red and he looks down at his hands before he mumbles something. “Didn't quite catch that, punk.” 

“It's a sex thing, okay?” Steve spits out, looking mortified. Bucky can't quite believe the words he just heard come out of the man's mouth. 

“Did you just say what I think you did?” 

“That night before that morning in the gym we were experimenting with handcuffs,” Steve whispered in a rush. “The marks hadn't faded so I had to hide them.” Bucky stares at him open mouthed for at least thirty seconds before he can speak again.

“And in the kitchen?” He finally asks. 

“I think that must have been when we were talking about, uh, breath play. She wasn't actually applying any pressure.” Bucky sits back and pinches his own leg, making sure he's actually awake and having this conversation. 

“Okay. Why are you so distant and jumpy tonight?” He finally asks. Steve's face burns even darker. 

“I'm not sure you really want to know that.” Y/N is watching the two of them with curiosity as she talks with Bruce and Natasha. Bucky meets her eyes and licks his lips. She excuses herself and makes her way over to the two men. 

“Everything all right?” She asks, not backing down from Bucky's gaze. Steve actually whimpers when she touches him. 

“Just clearing up a few things with my best pal, Doll.” He says. “It's all adding up so far, but I'm still wondering why he isn't joining in with the rest of the team.” A knowing look crosses Y/N's face and she smiles. 

“Go ahead, Stevie.” She coos and strokes his thigh. “Tell Bucky what he wants to know.” Steve swallows hard but relaxes at her touch. 

“I'mwearingaplug.” He says as quickly as possible. 

“Did he just say-?” She nods.

“And who's idea was that?” She prompts Steve.   
“Mine.” Steve finally looks up at her and Bucky can practically smell the lust coming off his friend in waves and he shifts in his seat, suddenly feeling warm. Y/N lays her hand on his arm and she smiles wickedly.

“We don't do anything unless we both agree to it. And if we try something and either one of us don't like it, we stop. No questions asked. But...” She trails off and looks over her shoulder to make sure the team is distracted. Everyone is watching Tony lose spectacularly at darts against Clint. “If you have any doubts about how much your best friend enjoys being at my mercy, you could always come see for yourself.” Bucky's jaw drops and he looks at Steve, expecting him to protest. Steve is just watching him with dark, hooded eyes. He's squirming in his seat and can barely contain his arousal. 

“Are you serious? Did you seriously just proposition me?” 

“Don't think I haven't seen the way you look at Steve.” She says.

“And I know you look at _her_ when you think I'm not paying attention.” 

“So we're extending an invitation. No pressure. You can think about it. If you decide it's not your thing, we can just pretend this never happened.” Steve nods in agreement. “But if you decide to accept, well...” She pulls him closer. “You would look beautiful on your knees with Stevie.” An involuntary shiver of pure excitement goes through Bucky's body. 

Steve is doing all he can not to moan out loud, he's actually rutting against her hand. Y/N presses a gently kiss on his temple.

“I'll take care of you very soon. Why don't you say goodnight to Bucky and we'll leave.” Steve doesn't even look at him.

“'Night, Buck.” 

“'Night.” He replies, still unsure that any of this is happening. 

“Think about it,” she says with a smirk. “You know where to find us.” She leans in and kisses Bucky's cheek. “Have a good night, Sargent.” The two of them call over to the rest of the team before leaving. 

Bucky reaches across the bar and picks up a bottle of vodka and pours an unhealthy amount into a glass. He certainly has plenty to think about.


	2. Chapter 2

**Notes for the Chapter:**

> This is just pure sin. There's a tiny smidge of plot, but let's be real. It's just smutty smut.

The idea was intoxicating to him. Bucky spent over a week going over what he had learned about Steve and Y/N's relationship, and their invitation to join them. Thinking about finally exploring the feelings he had harbored since his teens, knowing that Steve may have felt it all those years as well; it made him slightly dizzy. And then there was Y/N, a woman he not only found very attractive, but he also cared a great deal for her. How could he possibly wrap his head around the fact that these two seemed to want him in ways he had only dreamed about.

Dreams that confused as much as they aroused him. 

He knew that he was sending mixed signals to them. Sometimes he would act as if they conversation had never taken place, like nothing had changed. Others, he would be so deep into his fantasy that just being in the same room as them was overwhelming and he would flee as subtly as possible. He could tell Steve just figured he wasn't interested. The easy affection between them began to feel a little strained, as if he wasn't sure it crossed some kind of line or not. 

One afternoon he was walking to the gym with plans on working off his sexual frustration, still trying to decide what he was going to do, when he heard the two of them talking. Out of curiosity he followed the sounds of their voices, finding Steve and Y/N in what appeared to be an argument. 

“Y/N, you don't need to leave, it's all gonna blow over.” _Leave?_ Bucky felt his stomach drop. 

“It's not like I would be gone for good, but maybe it's for the best if I just go visit my family for a week or so. Things changed that night, Steve, and it's my fault.” 

“I'm the one that suggested that whole thing! I could have left or safe worded at any time, but I wanted to push myself.” 

“But you didn't invite your best friend into our bedroom! I did.” Steve sighed and cupped her face in his hand, rubbing his thumb over her cheek. 

“Maybe that wasn't the best time or place to do it, but we both know it was going to happen sooner or later.” 

“I feel like he can barely look at me any more, Steve.” Y/N said sadly. “He probably thinks I'm twisted, and just too nice to come out and say it.”

“And what would that make me, then?” Steve replied. Bucky couldn't take it anymore. He stepped around the corner. Y/N let out a little gasp and pulled away from Steve.

“Bucky-” 

“I don't think you're twisted.” He blurted out. “Either of you.” Steve visibly relaxed. “You don't have to leave. Please don't leave.” He took a few steps towards them. 

“I don't want you to be uncomfortable.” She said. 

“I'm not. I swear, just…” He trailed off and looked down at his feet. He could feel the tips of his ears burn. “I wanted to, _want_ to say yes.” Steve opened his mouth to say something when the three of them heard talking and laughter coming towards them. 

“We should take this somewhere else.” Steve said, taking Y/N's hand and motioning for Bucky to follow. The three of them went to Steve and Y/N's rooms. Bucky started to pace while Steve sat down and pulled her onto his lap. 

“You want to accept.” She said calmly after a few moments of silence. “I'm sensing a 'but'.” 

“It's not really… I don't know.” Bucky stopped moving and looked over at the couple. “I mean, is this a one time deal? I don't want to come between you two.” He watched them share a look, like they were having a silent conversation. Steve smiled and nodded at her. They stood and Y/N took Bucky's hands. 

“This doesn't have to be more complicated than the three of us want to have some fun,” she told him. “However, I would like to try something real quick.” She stepped closer to him. Bucky could smell her perfume and he swallowed hard. Her hand ran up his chest and rested on his shoulder. “Okay?” She asked. Bucky let out a shaky exhale and nodded. Y/N went up on her tip toes and gently kissed the corner of his mouth. She pulled back, as if to give him a chance to change his mind. He briefly looked over at Steve, wondering if he was really all right with it. Steve's pupils were lust blown watching the two of them. Bucky shifted his eyes back to Y/N. “Still okay?” She whispered. Another nod. This time she kissed him fully on the mouth. 

He couldn't help the moan that left his throat and his hands went around her waist. All of her touches were delicate, but his fingers dug into her skin as if he were about to fall off the edge. Memories of kissing pretty girls somehow both flooded his mind, but also blurred in comparison to the woman currently kissing him senseless. And suddenly, the contact was broken. Bucky willed his eyes to open, to see her smiling face. 

“Wow.” He breathed. Y/N chuckled lightly and turned to Steve. When she saw his hand palming over his jeans she tsked and grabbed him by his shirt.

“Did I tell you you could touch?” Her tone was teasing, with an edge that sent a shiver through both men. She tugged Steve closer and gave them both a significant look. “Your turn, if you're still on board?” She directed the question at Bucky. 

“Yes.” He croaked out. Y/N cupped the back of their heads and guided their faces towards each other. Steve hesitated a bit, searching Bucky's face for any signs of aversion. When he saw none, he relaxed and let the kiss happen. The first thing Bucky thought was that it was different than kissing Y/N or any other woman, but it was still enjoyable. He could feel her fingers work through his hair, nails scratching at the sensitive skin at the nape of his neck. Steve sighed against his lips, ran his tongue over his mouth in a playful manner before pulling away. The three of them just stood together for a moment. 

“Did that feel like something any of us want to do only once?” Y/N asked. 

“No.” Bucky said instantly. It was his first taste, but he was already hooked. He licked his lips and imagined he could still taste the two of them. 

“Definitely not.” Steve said, still staring at Bucky. Y/N nudged him. 

“Maybe I'm the third wheel here.” She said, jokingly. Steve grinned at her and laced his fingers with hers.

“I think we all know you're the driver.” Her eyes darkened and she reached out to take Bucky's hand. 

“We should sit down and talk about a few things before this goes any further,” she said. “Is that okay with you, Buck?” He nodded and squeezed her hand. 

She walked him through how everything worked between Steve and her. The rules, put in place for safety, and to make sure everyone found pleasure and enjoyment; how hard limits were never to be ignored or pushed. 

“I know Steve mentioned that we talked about breath play at one point,” she said, with a serious look on her face. “I found the idea appealing, but in reality I hated it. It scared the hell out of me.” Steve rubbed her shoulders. 

“So that would be one of your 'hard limits'.” Bucky said, and looked over at his friend. “Do you have any?” Steve blushed.

“I wasn't a huge fan of breath play either, but not so far.” Bucky learned seemed to learn more and more about his best friend every day. 

“We tread lightly with anything new,” Y/N told him. “Start small and build up to something more intense.” 

“I'm new.” Bucky said quietly. She smiled at him in a way that made him want to squirm. 

“You are.” She stood up and nudged his legs open until she could stand between them. “That means I'm not going to fuck you… yet.” She stroked his hair and chuckled at the disappointment on his face. “We can still play. If you want.” 

“Ye-yes. I want to.” 

“Aw, do I make you nervous, Bucky?” She teased. “I think I like that. Now, if Stevie is on board with all this...” She shot him a look over her shoulder. 

“Very much so.” Steve replied. 

“Excellent.” She gripped Bucky's hair and gently but firmly pulled. He let out a low groan and met her eyes. “I'm going to leave the two of you alone for five minutes. You will both strip down to your underwear. When I come back, you will both be kneeling. Steve will show you the correct way. Do you understand?” 

“Yes.” She gave his hair a sharp tug. 

“Yes?” 

“Yes Ma'am.” 

“What is your color?” 

“G-green. Ma'am.” Her lips curved. 

“Good boy.” The praise sent a shiver through him. 

When she returned both men were kneeling with their arms held behind their backs, heads bowed. They heard her soft footsteps as she circled them. Bucky could see her bare legs but he resisted looking up to see if she was naked, remembering Steve's warning to remain still until she gave further instruction. Y/N finally stopped between them. 

“I find myself a little overwhelmed. Each of you are gorgeous on your own, but the two of you like this? Exquisite.” She touched her index fingers to their chins and encouraged them to look up at her. Bucky let out a groan before he could stop himself. She wore a short silk robe so delicate and sheer he could see her breasts through it. A pair of lace panties was her only other clothing. “Do you like it? It was a birthday gift from Stevie, although I think it was as much for him as it was for me.” Bucky only swallowed the lump in his throat and stared at her in response. She smiled. “I'll take that impressive tent in your skivvies as a 'yes'.” Bucky blushed and shifted on his knees. “I think it's about time we took this into the bedroom, follow me.” She walked away and the men scrambled to get to their feet. 

The bed was stripped down to the fitted sheet, and the lighting was dimmed. Bucky smelled the soft fragrance of lavender in the air and noticed a few candles burning on the dresser. Y/N dragged her nails down his chest, pulling another sound from his lips. 

“In here, you may both make as much noise as you wish,” she said. “I want to hear that you're enjoying yourselves.” She went to Steve and pulled him down for a sizzling kiss, all tongues and teeth. “Take 'em off, Stevie. And get on the bed.”

“Yes, Ma'am.” Steve rid himself of his boxer briefs and lay down on the mattress, propping himself up on his elbows so he could watch her and Bucky. His cock was fully hard, curling up towards his abdomen but he made no move to touch himself. Y/N took Bucky's human hand and guided it down the front of her panties. 

“Do you feel that,” she murmured. “How wet I am for my good boys?” She used his fingers to circle her clit. “I could just use you like this to get off. Leave you both throbbing and aching, desperate to be touched, to be allowed to come.” Her breath stuttered and she stilled his hand, pulling it out of her underwear. Bucky rubbed his fingers together, feeling her wetness. “Tell me, Bucky. Do you like to watch?” She nipped at his ear. 

“Watch?” The feeling of her teeth on his neck made it difficult for him to think. 

“Stevie wants you to watch us. It's one of his little fantasies, isn't that right?” 

“God yes,” Steve groaned and ran one of his hands over his hip. “Please touch me.” He whined. 

“Soon, pet.” Y/N promised. “I think it would be perfect to ease you into all of this.” She told Bucky. “I'm going to do all the things that drive Stevie absolutely crazy, while you stand and watch. Maybe you'll get some ideas.” Bucky bit his lip and looked away. “No, don't do that. Communication, remember?” She said seriously. 

“Can I… Touch myself while I watch?” He whispered. Y/N smirked. 

“Since you asked nicely, you may.” She cupped his erection and squeeze gently. “But don't you dare make yourself come. I want my lips around your cock before that happens.” She snapped the waistband of his boxers. “Take these off. If I look over at you I want a good view.” Y/N climbed onto the bed and ran her hands up Steve's legs. 

“Fuck.” Bucky muttered when he finally wrapped his fingers around his dick. 

“Is this everything you dreamed it would be so far?” Y/N purred, peppering Steve's skin with kisses. 

“It's _so_ much better,” he groaned. “I love you so fucking much.” 

“My sweet exhibitionist,” she bit down on one of his nipples. “Did you know your best friend was such a slut, Bucky? His cock is already leaking and I haven't even touched it.” Her hand hovered over it. “Should I stroke him? Let him fuck into my hand?” Bucky only moaned in reply, trying to keep his pace slow so he wouldn't explode already. “Oh, that sounds like a no to me, Stevie.” 

“Please.” 

“I have plans for this,” she ran a single finger up and down his shaft. “I want you writhing and begging.” She leaned over and opened a nightstand drawer, pulling out a bottle of lubricant. “Will you be able to contain yourself if I finger you or do you need a cock ring?” Steve shook his head.

“I can handle it.” 

“I've trained you well. Bucky? Come over here and sit on the bed with us.” He sat down and leaned against the headboard. Y/N slicked up her fingers and circled Steve's hole. “This is what we did before Steve slipped the plug in that night.” She told Bucky and slid one finger into Steve. 

“Oh fuck, babe.” Steve sighed. 

“I opened him up, nice and slow. I don't know how he got his pants on, I thought he would burst.” Bucky felt his orgasm coming and stopped stroking himself, squeezing the base of his dick. “And when we came back here, I put on a strap on and fucked him. Are you familiar with those?” She added another finger. 

“I-I've seen them before. In porn.” He started to stroke his cock again. 

“Aren't you full of surprises,” she laughed. “Give a man internet access and he will figure out how to jerk off to porn.” 

“I need more.” Steve moaned, pushing down on her fingers. 

“You want me to stop teasing?” She crooked her fingers and Steve arched off the mattress with a jolt, his cock drooling over his stomach. “Does that feel good, pet?” Y/N cooed.

“It f-feels amazing. Oh shiiiiit, Y/N please!” 

“Please, what? Fuck you with my fingers?” She rubbed firmly over his prostate. Bucky watched him struggle to keep his hands off his dick. “Don't you dare,” Y/N warned, but her tone was playful. “Isn't he beautiful, Bucky?” Her eyes devoured the sight in front of her. “I know how to keep him on the edge for _hours_. I hope I'll learn the same for you.” The idea somehow made him even harder and he felt his head swim a little. Bucky got lost in the image of himself, dripping and hard with her fingers buried in his ass and her mouth wrapped around his cock. It was only her reaching out and grabbing his wrist that stopped him before he came. 

“Fucking hell,” he panted. “That was close, sorry.” 

“No need to apologize, you're learning. But you may not touch yourself again.” His dick twitched. 

“Please?” He asked weakly. 

“Don't worry, I told you I want you in my mouth. You'll come when I suck you off.” 

“She's amazing, Buck.” Steve rolled his head to look at Bucky with hazy eyes. “Believe me, it's worth the wait-” he broke off with a loud cry. “Fuck! Y/N!” 

“Do you want a plug before I ride you, Stevie? Do you want your ass full while I fuck myself on your dick?” 

“Yes!” She slowly pulled her fingers out of him and left them for a moment. Steve tried to catch his breath as he looked over at Bucky again. Both men were flushed and panting. 

“You've been so good, Stevie. I have your favorite.” She came back completely naked and wasted no time pushing the black rubber plug into his hole. When it was fully seated in him she straddled his hips and rubbed the tip of his dick over her slick entrance. “Watch me take his cock, Bucky,” she moaned softly. “Watch him stretch my pussy open.” She sank down onto Steve, letting her head fall back and let out a blissful sigh. 

“Shit.” He muttered, watching her ride his best friend's dick. 

“Come over to this side of the bed,” she panted. “I want that perfect cock in my mouth.” Bucky stood on shaky legs and did as he was told. When her hand wrapped around him he practically growled. When she took him into her warm, wet mouth, his eyes rolled back into his head. Grunts filled the thick air of the room. Every time Y/N moaned the vibrations added to Bucky's pleasure. 

“I'm getting close, Y/N!” He gasped. She pulled away from him with an obscene pop. 

“I want you both to come.” She took him back in her mouth. He felt her tongue caress the sensitive spot under the head and she took his balls into her hand, rolling and squeezing them gently. His knees nearly buckled. Steve was thrusting up into her as she rode him, chasing his own end. 

“Fuck, I'm gonna- I'm coming!” Steve yelled. Y/N slammed her hips down and he went rigid. She swallowed around Bucky and he too fell off the edge, shooting down her throat with a long groan. She smiled around him, sucking and licking him through his release and the aftershocks until he was too sensitive and pulled away. 

“You're both absolutely stunning when you come.” She said with a wicked grin. Bucky sat down on the bed before he collapsed. 

“You didn't-?” 

“Not yet,” she purred. Y/N got off of Steve and dipped two fingers into her dripping pussy. “You both get to clean me up and finish the job. I want to see how well you work as a team.” She laid back and opened her legs. Steve's seed was slowly flowing out of her. Steve didn't hesitate and began to lap at her labia. Bucky was slower to move, but he nudged Steve over so he could get his mouth on her sex. His and Steve's tongues moved over her, occasionally bumping together in a filthy parody of a kiss. Her moans grew louder, urging them to continue. Bucky found her clit and gently sucked on it, swirling his tongue over the bundle of nerves. “Oh fu-uck! Right there, don't you dare fucking stop!” They licked and sucked at her, not letting up until she exploded and her thighs trembled from over stimulation. She pushed herself up on her elbows and smiled lazily at them. “Wow. You boys sure you haven't done this before?” 

“Pretty sure,” Steve replied with his own grin. “You look so gorgeous and fucked out right now.” He pressed a kiss to the inside of her thigh. 

“I can say the same of you two. How did I get so lucky?” Bucky grabbed her hand and pulled her up so he could kiss her. His chin was still wet with her release. 

“I can stay?” He asked quietly when he pulled away. 

“Oh honey, we're keeping you.” She told him. “I'm not giving up either one of my boys.” Bucky smiled. 

“I think I like being yours.” Y/N wiped at his face with her thumb. 

“We need a shower.” Steve scooped her into his arms and she shrieked in surprise before dissolving into giggles. 

“You heard the lady, Buck.” He began carrying her towards the bathroom. Bucky grinned and followed, joining in Y/N's laughter.

**Notes for the Chapter:**

> Thanks for reading! This was the hardest (hehe) smut I've ever written. Adding that third person really threw me off for a while, so I'm sorry that it took so long for me to update. If you're on tumblr, this will be available on there as well, same user name as here; come say hello!

**Author's Note:**

> This is also available on my tumblr, which can be found under the same name as here; buriednurbckyrd. Thank you for reading!


End file.
